Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND SYSTEM FOR EXTRACTION OF HYDROCARBONS FROM
OIL SHALE
Field of the Invention
The present invention relates to using alternative energy sources to create a
method and
system that minimizes the cost of producing useable hydrocarbons from
hydrocarbon-rich shales
or "oil shales". The advantageous design of the present invention, which
includes a system and
method for the recovery of hydrocarbons, provides several benefits including
minimizing energy
input costs, limiting water use and reducing the emission of greenhouse gases
and other
emissions and effluents, such as carbon dioxide and other gases and liquids.
Background of the Invention
Discovery of improved and economical systems and methods for extracting
hydrocarbons
from organic-rich rock formations, such as oil shale, has been a challenge for
many years.
Historically, a substantial amount of hydrocarbons are produced from
subterranean reservoirs.
The reservoirs can include organic-rich shale from which the hydrocarbons
derive. The
shale contains a hydrocarbon precursor known as kerogen. Kerogen is a complex
organic
material that can mature naturally to hydrocarbons when it is exposed to
temperatures over 100
C. This process, however, can be extremely slow and takes place over geologic
time.
Immature oil shale formations are those that have yet to liberate their
kerogen in the form
of hydrocarbons. These organic rich rock formations represent a vast untapped
energy source.
The kerogen, however, must be recovered from the oil shale formations, which
under prior
known methods can be a complex and expensive undertaking, which may have a
negative
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environmental impact such as greenhouse gases and other emissions and
effluents, such as
carbon dioxide and other gases and liquids.
In a known method, kerogen-bearing oil shale near the surface can be mined and
crushed
. and, in a process known as retorting, the crushed shale can then be heated
to high temperatures to =
convert the kerogen to liquid hydrocarbons. There are, however, a number of
drawbacks to =
surface production of shale oil including high costs of mining, crushing, and
retorting the shale
and a negative environmental impact, which also includes the cost of shale
rubble disposal, site =
remediation and cleanup. In addition, many oil shale deposits are at depths
that make surface
mining impractical.
=
=
Attempts have been made to overcome the drawbacks of prior known methods of
=
recovery by erriploying in . situ (i.e., "in' place") = processes. In situ
processes can include
techniques whereby the kerogen is subjected to in situ heating through
combustion,- heating with
other material or by electric heaters and radio frequencies in the shale
formation itself. The shale
= is retorted and the resulting oil drained to the bottom of the rubble
such that the oil is produced
from wells. In still other attempts, in situ techniques have been described
that ,inc.lude fracturing
= and heating the shale formations underground to = release gases .and
oils. These types of
techniques typically require finished hydroCarbons to produce thermal and
electric energy and
heat the shale, and may employ conventional hydro-fracturing techniques or
*explosive materials.
These attempts, however, also continue to suffer from disadvantages such . as
negative
environmental impacts, high fuel 'costs to produce thermal energy for heating
and/or electricity,
as, well as high water consumption. In addition, these methods may have, a
negative . .
environmental impact 'such: as greenhouse gases and other emissions and
effluents, such' as
carbon dioxide and other gases and liquids..
Therefore, it would be desirable. to overcome the disadvantages and drawbacks
of the
prior art with a method and system for recovering hydrocarbon products from
rock formations,
such as oil shale, which heat the oil shale via thermal or electrically
induced energy produCed by
a nuclear reactor. It would be desirable if the. method and system can
accelerate the maturation
process of the predursors of crude oil and natural gas. It is most desirable
'that the method and =
system of the present invention is advantageously employed to minimize energy
input costs,
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limit water use and reduce the emission of greenhouse gases and other
emissions and effluents,
such as carbon dioxide and other gases and liquids.
Summary of the Invention
Accordingly, a method and system is disclosed for recovering hydrocarbon
products from
rock formations, such as oil shale, which heat the oil shale via thermal
energy produced by a
nuclear reactor for overcoming the disadvantages and drawbacks of the prior
art. Desirably, the
method and system can accelerate the maturation process of the precursors of
crude oil and
natural gas. The method and system may be advantageously employed to minimize
energy input
= costs, limit water use .and reduce the emission of- greenhouse gases and
other emissions and
effluents, such as carbon dioxide and other gases and liquids. =
õ .
In the method and system it is contemplated that supercritical material will
be injected
= : .
into the formation to produce fracturing and porosity that will Maximize the
production of useful =
=
hydrocarbons from the oil shale formation.
=
In one particular embodiment, in accordance with the present disclosure, a
method for
recovering hydrocarbon products is provided. The method includes the steps of:
producing
thermal-energy using a nuclear reactor; providing the thermal energy to. a hot
gas generator;
providing a gas to the hot gas generator; producing a high pressure hot gas
flow from the hot gas
generator using a high, pressure pump; injecting the high pressure hot gas
flow into injection
= wells wherein the injection wells are disposed in an oil shale formation;
retorting oil shale in the .
shale oil formation using heat from the hot gas flow to produce hydrocarbon -
products;= and
extracting the hydrocarbon products from the recovery well
In an alternate embOdiment, the method includes the steps of: generating
electricity using
a nuclear powered steam turbine; retorting oil shale in a shale oil formation
using electric heaters
powered by. the electricity to produce hydrocarbon products and extracting the
hydrocarbon
products from the injection well.
In another .alternate embodiment, the method includes the steps of: producing
thermal
energy using a nuclear reactor; providing the thermal energy to a molten
salt.or liquid metal
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generator; providing a salt or metal to the molten salt or liquid metal
generator; producing a
. molten salt or liquid metal flow from the molten salt or liquid.metal.
generator using a pump;
injecting the molten salt or liquid metal flow into bayonet injection wells
wherein the injection
. wells are disposed.in an oil shale formation; retorting oil .shale in the
shale oil formation using
heat from the molten salt or liquid metal flow to produce hydrocarbon
products;. and extracting =
the hydrocarbon products from the recovery well.
In another.alternate embodiment; the method includes the steps of: generating
electricity =
using a nuclear powered steam turbine; retorting oil' shale in a shale oil
formation: using radio
frequencies powered by the electricity tO produce hydrocarbon products; and
extracting the =
hydroCarbon products from the recovery well. = =
The present invention provides a system and method for extracting hydrocarbon
products
from oil shale. using ruiclear reactor sources for energy to fracture the oil
shale formations and =
'.provide sufficient heat and/or *electric power -to produce liquid 'and
gaseous . hydrocarbon
products. Embodiments of the present invention also disclose steps for
extracting the
hydrocarbon products from the oil.shale formations. =
= =
.=
Oil shale contains the preCursors of crude oil and natural gas. The method and
system can
be employed to artificially speed the maturation process of these precursors
by first fracturing the
= formation Using supercritical materials to increase both porosity and
permeability, and then heat =
the shale to increase the temperature of the formation above naturally
occurring heat created by
an overburden pressure. The use of a nuclear reactor may reduce energy input
cost as compared .
to employing .finished hydrocarbons to produce. thermal.energy and/or
electricity. Nuclear =
- reactors produce the supercritical temperature in the range from 200 to
1100* C (depending on
the material to be used) necessary for increasing the pressure Used in the
fracturing process =
compared to conventional. hydro fracturing and/or the use of explosives. In -
oil shale, the
maximization .of fracturing =is advantageous to hydrocarbonaccurn. ulation and
recovery.
= .
Generally, massive shales in their natural state have.very limited
permeability and porosity. = =
=
In addition, limiting water use is also beneficial. The use of large
quantities of water has
.downstream implications in terms. of water availability and pollution. The
method and system
may significantly reduce water use.
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Further, the use of natural gas/coal/oil for an input energy source creates
greenhouse
gases and other emissions and effluents, such as carbon dioxide and other
gases. An increasingly
. large number of earth scientists believe that greenhouse gases contribute
to a phenomenon
= popularly.described as "global warming". The method and system of the
present disclosure can
significantly reduce the emission of greenhouse gases.
*. =
= .Brief Description of the Drawings
= The present invention, both as to its organization and manner of
operation, will be more
fully understood from the following detailed description of illustrative
embodiments taken in =
conjunction'with.the accompanying drawings in which:
Figure 1 is a schematic diagram of a rriethod and system for fracturing oil
shale using a
= nuclear energy source in accordance with the principles.of the present
invention;
= Figure .2 is a schematic diagram of directionally -drilled. shafts used
at an extraction site, .
in accordance with.the principles of the present invention;
= Figure 3 is a process energy flow diagram of the method and system shown
in Figure 1;
Figure 4 is. a .schematic diagram of a.method- and system for retorting oil
shale using a
nuclear energy sciurce in accordance.with the principles of the present
invention;
-
Figure 5 is a process energy flow diagram of the method and, system shown 'in
Figure 4;
. Figure 6 is a schematic diagram of an alternate embodiment of the method and
system
shown in Figure 4;
=
Figure 7 is a process energy flow diagram of the method and system shown in
Figure 6;
= Figure 8 is a schematic diagram of. an alternate embodiment of the method
and system =
shown in Figure 4;=
= =
= Figure 9 is a process energy flow diagram of the method and system shown
in Figure 8;
==
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.
.
Figure 10 is. a schematic diagram of an alternate embodiment of the method,
and system ==--
shown in Figure 4; and
=
.
Figure 11 is a process energy flow diagram of the method and system
shown in Figure
10.
=
=
Detailed Description =. = . = =
. .
The exemplary embodiments of the method and system for extracting =hydrocarbon
products using alternative energy sources to fracture oil shale fortnations
and heat the shale to =
. produce liquid and gaseous hydrocarbon products are discussed in terms of
recoVering
hydrocarbon products from rock formations and more particularly, in terms of
recovering such
hydrocarbon products from the Oil Shale via thermal energy produced by a
nuclear reactor. The
method and system .of recovering hydrocarbons- may accelerate the maturation
process of the
precursors of crude oil and natural gas. It is contemplated that such a method
and system as = =
disclosed herein can be employed to minimize energy input costs:limit water
use and reduce the
emission of greenhouse gases and other emissions and effluents, such as carbon
dioxide and =
other gases and liquid. The use of a nuclear reactor to produce thermal energy
.reduces energy
input costs and avoids reliance on finished hydrocarbon products to produce
thermal energy and
the related drawbacks associated therewith and discussed herein. It is
envisioned that the present
disclosure may be employed with a range of recovery = applications for oil
shale extraction =
including other in situ techniques, such as combustion and alternative heating
processes, and
surface. production methods. It is further envisioned that the present
disclosure may be used for
the recovery of materials other than hydrocarbons or their precursors disposed
in subterranean
locations.
=
The following discussion includes a description of the method and system for
recovering =
hydrocarbons in accordance " with the.- principles of the .present disclosure.
Alternate
=
= 25
embodiments are also disclosed. Reference will now be made in
detail to the exemplary =
embodiments of the present disclosure, which are illustrated in the
accompanying figures.
Turning now to Figure 1, there is illustrated a method and system for
recovering hydrocarbon =
products, such as, for example, a system 20 for fracturing and retorting oil
shale using a nuclear'
=
6 .
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reactor and an associated thermal transfer system, in = accordance with the
principles of the
present disclosure.
The nuclear reactor and thermal components of system 20 . are suitable for
recovery
applications.. Examples of such nuclear reactor and thermal components are
provided herein,
although alternative equipment may be selected and/or preferred, as determined
by one skilled in
the art.=
. . .
. .
. = =
Detailed embodiments of the present disclosure are disclosed herein, however,
it is to be
understood that the described embodiments are merely exemplary of the
disclosure, which may
be embodied in various form's. Therefore, specific functional details
disclosed herein are not to -
be interpreted as limiting, but merely as a basis for the claims and as a
representative basis for
teaching one .skilled in the art to variously employ the present disclosure in
virtually any
= appropriately detailed embodiment.
= =
= In one aspect of system 20 and its associated method of operation, an oil
shale extraction
site 22 is selected for recovery of hydrocarbon products and treatment of the
precursors of oil
and gas. Site s.election will be based on subsurface mapping using existing
borehole data such as .
well logs and core samples and ultimately data from new holes drilled in a
regular grid. Areas
= with higher concentrations of relatively mature kerogen and lithology
favorable to fracturing will
be selected. Geophysical well log data where available, including resistivity,
conductivity, sonic
logs and so on will be employed.. Seismic data is desirable; however, core
analysis is a reliable
method Of determining, actual porosity and permeability which is related to
both efficient heating
and extraction of the end product, usable hydrocarbons. Grain size and
distribution is also
desirable as shales give way to sands. Areas where there is high
drilling,ensity and reliable data.
with positive indications=in the data would be ideal. Geochemical analysis is
also desirable to the.
process as shales tend 'to have very complicated geochemical characteristics.
Surface
geochemistry is desirable in a localized sense. Structural features and
depositional environments
= are desirable in a more area or regional sense. Reconstaiction of
depositional environments and
post-depositional dynamics are desirable. For instance, oil shales along the
central coast of
California feature a great deal of natural fracturing due to post-depositional
folding and
fracturing of the beds. Three dimensional computer modeling provided there is
enough accurate =
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data would be desirable. As experience is gained in the optimal parameters for
exploitation, the
entire process and system can be modulated tn = its application to different
sub-surface
environments. At selected site 22, a surface level 24 is drilled for
extraction of core samples (not .
shown) using *suitable drilling equipment. for a rock formation application,
as is known to one
= skilled in the art. The -core samples are extracted from site 22 and
geological information is
taken from the core samples. These core samples are analyzed to determine if
site 22 selected is
suitable for recovery of hydrocarbons and treatment of the precursors of oil
and gas.
=
= =
If the core samples have the desired characteristics; site 22 will be deerned
suitable fee
attempting to extract hydrocarbons from oil shale. Accordingly, a strategy and
design is
10. formulated for constructing fracturing wells and retort injection wells,
as wilt be discussed
below. Joints, fractures and depositional weaknesses will be exploited in
order to maximize the
effect of this method of fracturing. Ideally areas can be identified which
have experienced a .
relatively higher.degree of naturally occurring fracturing due to folding and
faulting as observed
in the coastal areas of central California. Piping arrays will be oriented in
.concert with these
existing weaknesses in order to create the maximum disruption of the rock
matrix. The nuclear
reactor placement will also .be -formulated and planned for implementation, as
well any other
infrastructure placements necessary; for implementation of the system and
method. It is
contemplated that if the core samples taken -from the selected site are not
found to have the
desired characteristics, an alternate site may be selected. Site 22 is also
prepared for installation
and related construction of a supercritical material generator 28 and other
components including
high pressure pumps 30 and drilling equipment (not shown).
=
In another aspect Of system" 20, installation and related construction of
nuclear reactor 26
and the components of the thermal transfer system at site 22 is performed.
Plumbing eqUipment
(not shown) is constructed and inStalled. A material supply 34 is cdrinected
to the 'plumbing
equipment and the components of the thermal transfer system. Electrical
equipment (not shown)
is wired 'and installed. Off-site electric connections (if available) 'are
made to the electrical
.
' equipment. If off-site electric connections are not available, then a
small stream of energy from
the nuclear reactor may be generated using a conventional electric generator
(not shown). it is
,
.contemplated that plumbing equipment and electrical eqUipment are employed
that are suitable
8
CA 02641521 2013-11-08
for an oil shale extraction application and more particularly, for recovery of
hydrocarbons and
treatment of their precursors, as is known to one skilled in the art.
It is envisioned that nuclear reactor 26 may be a small or large scale nuclear
reactor
employed with system 20 in accordance with the principles of the present
disclosure. Nuclear
reactor 26 is a thermal source used to provide thermal energy 32 to fracture
an oil shale
formation (not shown). Nuclear reactor 26 is sized to be located at or near
the oil shale
formation of site 22. It is envisioned that the thermal rating of nuclear
reactor 26 is between 20
MWth to 3000 MWth. For example, a nuclear reactor, such as the Toshiba 4S
reactor, may be
used. These reactors can include all generation III, III+ and IV reactors,
including but not
limited to Pressurized Water Reactors, Boiling Water Reactors, CANDU reactors,
Advanced Gas
Reactors, ESBWR, Very High Temperature Reactors, helium or other gas cooled
reactors, liquid
sodium cooled reactors, liquid lead cooled rectors or other liquid metal
cooled reactors, molten
salt reactors, Super Critical Water Reactors, and all next generation nuclear
plant designs.
Supercritical material generator 28 is constructed and installed at site 22.
Nuclear reactor
26 is coupled to supercritical material generator 28, as is known to one
skilled in the art, for the
transfer of thermal energy 32. Material supply source 34 delivers material 35
to supercritical
material generator 28. System 20 employs supercritical material generator 28,
in cooperation
with nuclear reactor 26 as the thermal source, to produce supercritical
material 36 for fracturing
oil shale formations. It is contemplated that a number of materials may be
generated by
supercritical material generator 28 for fracturing, such as water, carbon
dioxide and nitrogen,
among others.
The use of supercritical material 36 is employed to enhance permeability and
porosity of
the oil shale formation through fracturing. Studies have shown that
supercritical material can be
effectively used to permeate and fracture rock formations. (See, e.g., 14th
International
Conference on the Properties of Water and Steam in Kyoto, Sergei Fomin*, Shin-
ichi Takizawa
and Toshiyuki Hashida, Mathematical Model of the Laboratory Experiment that
Simulates the
Hydraulic Fracturing of Rocks under Supercritical Water Conditions, Fracture
and Reliability
Research Institute, Tohoku University, Sendai 980-8579, Japan). Other
supercritical material
has been used in other applications.
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Systems to manage the extremely high pressures .must be installed in order to
safely
operate the entire apparatus. Placement of blowout preventers and pressure
relief valves will be
= integrated into the system and carefully monitored particularly at the
outset of testing the
= process. =
= High pressure pumps 30 are installed at site 22 and coupled to,
supercritical material .
generator 28 for injecting supercritical material 36 into the oil shale
formations. High pressure . = .
purrips 30 deliver supercritical material 36 to oil shale fracturing wells 38
at high pressure.
=
Supercritical material 36. is delivered at high pressures to the oil shale
formations to achieve
maximum permeability in the shale. It is envisioned that high pressure pumps
30 deliver
.10 pressures in the range between 50 and 500 IVIPa or higher. These pumps
may be Centrifugal or
other types of pumps. The high pressure pumps and required remote pumping
stations (not =
= shown) may be 'designed for remote operation using the pipeline SCADA
(Supervisory Control. = =
=
. And Data Acquisition) systems and may b.e equipped with protection
equiprrient such as intake
= and discharge .pressure controllers and automatic shutoff devices in caSe
of departure from
=
design operating conditions.. ,
=
= =
It is further envisioned that an optimal injectio.n parameters can. be
determined based on
the formation characteristics and other factors. Geologic environments can
vary locally and
. regionally. As well as discussed above, System 20 may include various
high pressure pump .
configurations such as a series of multiple pumps to achieve optimal results.
The described
supercritical material distribution system is constructed and installed at
site 22, as is known to
one skilled in the art. All systems are tested and a shakedown integration is
performed.
= An infrastructure 39 for fracturing wells 38 (Figure 1) is constructed at
site 22, as shown
in Figure 2. A drilling rig 40 with equipment designed for accurate
directional drilling is brought = =
on site. It will be 'very important to accurately determine the location of
the bit while drilling. .
= Many recent innovations in rig and equipment design make this possible. Rigs
may be-leased on
= a day or foot rate and.are brought in piece by piece for large rigs and
can be truck mounted for
small rigs..Truck mounted rigs can drill to depths of 2200 feet or more 24 of
site 22, as is known .
to one skilled in the art. Drilling rig 40 is. disposed adjacent a vertical
drill hole 42 from which
horizontal drill holes = 44, which may be disposed at orthogonal, angular or
non-orthogonal
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=
orientations relative to vertical drill hole 42, are .formed. Oil 'shale
fracturing wells 38 are
installed with infrastructure 39 of site 22. Oil shale fracturing wells 38
inject supercritical
material 36 into drill holes 42, 44 of the oil shale formation and site 22.
= Directional drilling is employed to maximize the increase in permeability
and porosity' of .
the oil shale formation and maximize the oil shale formation's exposure to
induced heat. -The .
configuration of horizontal drill holes.44 can be formulated based on
geological characteristics.
= of the oil shale formation as=deterinined by core drilling and
geophysical investigation. These
characteristics include depositional unconformities,=orientation of the
bedding planes, schistosity,
as' well as structural disruptions within the shales as a consequence of
tectonics. Existing
weaknesses in. the oil shale formations may be exploited including
depositional unconformities, =
stress fractures and faulting.
=
=
An' illustration of the energy flow of system 20 for oil shale fracturing
operations (Figure
- I.); as shown in Figure 3, includes nuclear energy 46 generated from nuelear
reactor '26. Nuclear
energy 46 'creates thermal energy 32 that is transferred to supercritical
material generator 28 for =
=
producing' supercritical material 36. Supercritical material 36 is delivered
to high pressure
pumps 30. Pump energy 48 puts supercritical material 36 under high pressure.
, High pressure pumps 30 deliver 'supercritical material 36 to
fracturing wells 38 with
sufficient energy 50 to- cause fracturing in the oil shale formations.' Such
fracturing force
increases porosity- and permeability of the oil shale formation through
hydraulic stimulation
under supercritical conditions. Residual supercritical materials from the
fracturing operations are
= recovered via a rri. aterial recovery system 45 and re-introduced to
supercritical material generator
28 via material supply 34 using suitable conduits, as known to one skilled. in
the art. It is
envisioned that a material recovery system is. employed to minimize the
consumption of material.
=
,used to fracture the oil shale formation. A recycling system may
be deployed in order to also. .
minimize any groundwater pollution and reCycle material where possible. =
= =
=
In another aspect of system 20, the fracturing operations employing the
supercritical
material distribution system described and oil shale fracturing well's 38 are
initiated. Nuclear
reactor 26 and the material distribution system are run. Fracturing of the oil
shale formations via
wells 38 is conducted to increase permeability and porosity of the oil shale
formation for heat
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inducement. The fracturing process in the oil shale formation at site 22 is
tracked via readings
= taken. Based on these reading values, formulations are conducted to
determine when the
fracturing is advanced to a desired level. One method of determining the level
of fracturing
would be take some- type of basically inert material, circulate it downhole,
and read the amount
=.
= and rate of material Joss. In other words, measure the "leakage" .into he
formation. Gases may ==
also be employed With the amount of pressure- loss being uSed to measure the
degree of
-fracturing. These measurements would be compared to "pre-fracturing" level.
This method
would be particularly helpful in the case of microfracturing. Core samples*are
extrabted from the
=
fractured oil shale. formation. These samples are analyzed. The analysis
results are used to
. formulate and plan for implementation of a drilling scheme for the injection
wells for retort and
perforation wells for product recovery. =
=
=
=
= In another aspect of system 20, oil shale fracturing wells* 38 are
dismantled from
'infrastructure 39. Initially, operation of nuclear reactor 26 is temporarily
discontinued in cold or
hot shutdown depending on the particular reactor's characteristics. Oil. shale
fracturing=wells 38
are dismantled and removed from infrastructure 39 of site 22. Retort wells and
perforation-
recovery wells (not shown) are constructed with infrastructure 39, in place of
the oil shale
fraCturing wells 38, and installed at site. 22 for connection with drill holes
42, 44. :Exemplary
embodiments of retort systems for use With system 20; in accordance with the
principles of the
present disclosure, will be desbribed-in detail with regard to Figures 4:11
discussed below.- =
90
= = The retort wells -transfer heated materials to the fractured oil shale
formations for. heat
= .
inducement. The exposure of the oil shale to heat in connection with high
presgure accelerates
the maturation of the hydroCarbon precursors, such as kerogen, which forms
liquefied and
gaseous hydrocarbon products. During the retort operatiOns, hydrocuarbons
accumulate. A =
= .
suitable recovery system is constructed for hydrocarbon recovery, as Will be
discussed. Nuclear
-reactor 26 is restarted for retort operations, as described.. All-systems are
tested and a, shakedown
integration is performed.
=
. = =
=
' In another aspect of system 20, the retort operations employing the re-tort
=wells.and
perforation recovery wells-are initiated I.& product recovery. The-retort
wells and the perforation =
wells are run and operational. In one particular embodiment, as shown in
Figure 4, system 20
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includes a retort system 120 for retort operations relating to the fractured
oil shale formations at
site 22, similar to that described with regard to Figures 1-3. Site 22 is
prepared for installation
and related construction of retort system 120, which inchideS gas handling
equipment and
thermal transfer system components, which will be described.
=
Retort system 120 employs hot gases' that are injected into the fractured, oil
shale
formations to induce heating and accelerate the maturation process of
hydrocarbon precursors as .
= =
diScussed.. Nuclear reactor 26 discussed above, is a thermal source
that provides thermal. energy
132 to retort the oil shale formation in-situ. Nuclear reactor 26 is sized to
be located at or near
= site 22 of the fractured oil shale formation.õ It is envisioned that the'
thermal rating of nuClear
10.
reactor 26 is between 20 MWth to 3000 MWth. It is further' contemplated
that hydrogen
generated by nuclear, reactor 26 can be used to enhance the value of carbon
bearing material,
. . which may resemble char and, be. recoverable. A hydrogen generator
(not shown), either
electrolysis, thermal or other may be attached to the nuclear reactor 26 to
generate hydrogen for
= this Use.
=
15. =
A gas injection system 134 is.installed at site 22. Gas injection
systein 134 delivers gas
to.a hot gas generator 128. Hot gas generator 128 is constructed and installed
at bite 22.. There
are many types of hot gas generators available .for this type of application
including, but not
=
limited to boilers and the like. Nuclear reactor 26 is coupled to hot gas
generator 128; as is
known to one skilled in the art, for the transfer of thermal energy 132.
System 20 employs hot
20
gas generator 128, in cooperation with nuclear reactor 26 as the. thermal
source, to produce hot
gas 136 for retort of the fractured oil shale formations.
=
=
=
It is envisioned.that the thermal output of nuclear reactor 26 can be used to
heat various
= types of gases for injection to retort the oil shale formations such as
air, carbon dioxide, oxygen,.
.
nitrogen, methane, acetic acid, steam or. other appropriate gases other
appropriate combinations.
25 Other gases can also be injected secondarily to rriaximize=the
retort.prOcess if appropriate. .
High pressure.pumps 130 are installed at site 22 and coupled to hot gas
generator 128 for
injecting hot gas 136 into the fractured oil shale formations. High pressure
pump. s 130 put hot_
= gas 136 into a high pressUre state to promote the, retort of the oil
shale tbrmations. It is =
13.
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=
envisioned that system 20 may include various high pressure pump
configurations including
multiple pumps and multiple gases to maximize the effectiveness of the retort
operation.
=
Oil shale asset heating retort injection wells 138 are installed with the
infrastructure. of= =
system 20, as discussed. Hot gas 136 is transferred to injection wells 138 and
injected into the = =
=
fractured oil. shale formation. The use of hbrizontal drilling deScribed with
regard to Figure 3,
can be employed to maximize the oil shale formation's exposure to heat
necessary to form both
gaseous and liquefied hydrocarbons. It may take between 2-4 years for the
formation of .
sufficient kero&n to be commercially recoverable. After that :recovery may
occur on a
= cornmercial level for between 3 ¨ 30 years or more.
=
A product recovery system 160 is. constructed at site 22. Product recovery
system 160
may be a conventional hydrocarbon recovery system or other suitable systerr.
that addresses the
recovery requirements and is= coupled with perforation recovery wells .120
(not sho.wn) for
=
collection of gaseous and liquefied hydrocarbons that are released during the
reto-rt process. .An
illustration of the energy flow of. system 20 with retort system 120 for oil
shale retorting
= operations (Figure 4), as shown in Figure 5, include.s nuclear energy 146
generated from nuclear
reactor 26. Gas is 'delivered from 'gas injection system 134 to hot gas
.generator 128. Nuclear
energy 146 creates thermal energy 132 that is transferred to hot gas generator
128 for producing
hot gas 136. Hot gas 136 is delivered to high pressure pumps 130. Pump energy
148 puts hot
=
gas .136 under high pressure.
=
. = 20 .. High pressure pumps 130 deliver hot gas 136 to retort injection
wells 138 with sufficient
energy 150 to transfer hot as 136 *to the fractured oil shale formations for
heat inducement for
retort operations. The expOsure= of the oil shale to heat in connection with
high pressure =
accelerates the maturation of the hydrocarbon precursors, such as kerogen,
which forms liquefied
and gaseous hydrocarbons. *During the retort operations, hydrocarbon products
162 accumulate. =
Hydrocarbon products 162 are extracted and collected by product recovery
system 160. Residual .
gas from the retorting operations is recovered via a gas recycle system 145
and reinjected' to hot. .
gas generator 128 via gas injection system' 134. It is envisioned that a gas
recovery'system is
employed to minimize the consiiniption of gas used to retort the fractured oil
shale formation.
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In an alternate embodiment, as shown in Figure. 6, system 20 includes a retort
system. 220
for .retort operations relating to the fractured oil shale formations at site
22, similar to those
described. Site 22 is prepared for installation and related construction of
retort system 220;
=
=
which includes a steam generator and thermal transfer system components, as
will be described.
. Retort system 220 employs heat generated bY electric heaters inserted
into holes drilled
. =
into the fractured -oil shale formations of site 22: The heat generated
induces heating of the
fractured oil shale formations to accelerate the maturation process of
hydrogen precursors, as
.= discussed. Nuclear reactor 26 discussed above, is a thermal source that
cooperates with a steam
generator 228 .to power a .Steam..turbine 230 for generating steam that may be
used to drive an
electric generator 234 to produce the electric energy to retort the fractured
oil shale formation in-
situ. If a conventional Pressurized Water Reactor or similar non-boiling water
reactor is used a
heat exchanger (not shown) may be required. Nuclear reactor 26 is sized to be
located at or near .
site 22 of the fractured oil Shale formation. It is envisioned that the
electric capacity rating of
nuclear reaCtor 26 is between 50. MWe to 2000 MWe. It iS contemplated .that
the hydrogen = -
.15 generated by nuclear reactor 26 can be used to enhance the value of
carbon bearing material,
whiCh may resemble char, sb. it will be -recoverable. A hydrogen generator
(not shown), either
electrolysis, thermal or other may be attached to the nuclear reactor 26 to
generate hydrogen for .
this use.
. .
=
Water supply 34 deliyers water to steam generator 228, which is constructed
and installed .
at site 22. Nuclear reactor 26.is coupled to steam generator 228, aS is known
to one skilled in the
. art, for the transfer of thermal energy 232. . 'System 20 erriProys steam
generator 228, in
cooperation with nuclear reactor 26 as the thermal source, to produce steam
236 to activate steam
turbine 230 for operating an electric generator to provide electric eneily for
the retort of th&
fractured oil shale formations. . If a conventional Pressurized Water Reactor
or similar non-
boiling water reactor is used a heat exchanger (not shown) may be required:
=
Steam generator 228 is coupled' to.steam. turbine 230, in a manner as is known
to one
=
skilled in the art. Stearn 236 from steam generator 228 flows into steam
turbine 230 to provide
mechanical energy 237 to an electric generator 234. 'Steam turbine 230 is
coupled to electric
generator 234, in a manner as is known to one skilled in the art, and
mechanical energy 237
=
CA 02641521 2013-11-08
generates current 239 from electric generator 234. It is contemplated that
current 239 may
include alternating current or direct current.
Current 239 from electric generator 234 is delivered to oil shale asset
electric heating
retort injection wells 238. Injection wells 238 employ electric resistance
heaters (not shown),
which are mounted with holes drilled into the fractured oil shale formations
of site 22, to
promote the retort of the oil shale (See, for example, discussion in "Shell to
take 61% stake in
China Oil Shale Venture", Green Car Congress, Internet article, September 1,
2005. The electric
resistance heaters heat the subsurface of fractured oil shale formations to
approximately 343
degrees C (650 degrees F) over a 3 to 4 year period. Upon duration of this
time period,
production of both gaseous and liquefied hydrocarbons are recovered in a
product recovery
system 260.
Product recovery system 260 is constructed at site 22. Product recovery system
260 is
coupled with injection wells 238 or perforation recovery wells for collection
of gaseous and
liquefied hydrocarbons that are released during the retort process. An
illustration of the energy
flow of system 20 with retort system 220 (Figure 6) for oil shale retorting
operations, as shown
in Figure 7, includes nuclear energy 246 generated from nuclear reactor 26.
Nuclear energy 246
creates thermal energy 232 that is transferred to steam generator 228 for
producing steam 236.
If a conventional Pressurized Water Reactor or similar non-boiling water
reactor is used a heat
exchanger (not shown) may be required. Steam 236 is delivered to steam turbine
230, which
produces mechanical energy 237. Mechanical energy 237 generates current 239
from electric
generator 234.
Current 239 delivers electric energy 241 to the electric heating elements to
heat the
fractured oil shale formations for heat inducement. The exposure of the oil
shale to heat
accelerates the maturation of the hydrocarbon precursors, such as kerogen,
which forms liquefied
and gaseous hydrocarbons. During the retort operations, hydrocarbon products
accumulate. The
hydrocarbon products are extracted and collected by product recovery system
260.
In another alternate embodiment, as shown in Figure 8, system 20 includes a
retort
system 320 for retort operations relating to the fractured oil shale
formations at site 22, similar to
that described. Site 22 is prepared for installation and related construction
of retort system 320.
16
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which includes a molten salt or liquid metal generator, bayonet heaters and
thermal transfer =
system components, which will be described.
=
Retort system 320 employ S molten salts dr liquid metal; which are injected
into the
. .
= fractured oil shale formations to accelerate the maturation proceSs of
hydrocarbon precursors as
discussed. Nuclear reactor 2:6 is' a thermal .source that provides thermal
energy 332 to retort the
fractured oil shale-formation in-situ. Nuclear reactor 26 is sized to be
located at or.near site 22 of
.
the fractured oil shale formation. It is envisioned that the thermal rating
of' nuclear.reactor.26 is.
between 20 MWth to 3000.MWth. It is further contemplated that hydrogen
generated by nuclear
. reactor 26 can be=used to enhance the value of carbon bearing material,
which may resemble char
and be recoverable. A hydrogen generator (not shown), either electrolysis,
thermal or Other may =
be attached to the nuclear reactor 26 to generate ,hydrogen for this use.
A salt injection system 334 is installed at site 22.. Salt injection system
334 .delivers salts =
= = to a molten salt generator 328. Molten salt generator 328 is
constructed and installed at site 22.
Nuclear reactor 26 is coupled to molten salt generator 328, as is known to one
skilled in the art,. =
for the transfer of thermal energy 332. System 20 employs molten Salt
generator 328, .in
cooperation with nuclear reactor 26 as the therrnal source, to produce molten
salt 336 for retort
of the fractured oil shale formations. =
.It is envisioned that the thermal output of nuclear reactor 26 can b.e used
to heat various .
types of salts for injection to retort the oil shale, such as halide salts,
nitrate salts, fluoride salts, :
. 20
and .chIciride salts. It is further envisioned that liquid metals may
be used.with retort system 320 =
as an=alternative to salts, which inCludes the use of a metal injection system
and a liquid metal
generator. The thermal output of nuclear reactor 26 can be used to heat
various types of metals
for injection to retort the'oil shale, including alkali metals such as sodium.
=
Pumps .330 are installed at site 22 and coupled to molten salt generator 328
for injecting = s
molten salt 336 into the fractured oil shale formations. Pumps 330 are coupled
to oil shale asset =
=
heating retort injection wells 338 .to deliver molten salt 336 for the retort
of the fractured, oil
shale formations. It =is:envisioned that system 20 may include various pump
Configurations
including Multiple pumps to maximize the effectiveness of the retort
operation. 'It is further
envisioned that pumps 331. may be, employed = to recover .residual molten,
salt, after retort .
17 =
=
CA 02641521 2008-08-06
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PCT/US2007/003098
operations, for return to molten salt generator 328, as part of the recovery
and recycling system
of system 320 discussed below.
Oil. shale asset heating= retort injection wells 3'38 are installed with the
infrastructure. of
=
system 20, as discussed. Molten salt 336 is transferred to injection wells 338
and injected into .
the fractured oil shale formation. The use of horiontal drilling described
With regard to Figure
= -3; can be employed to maximize the oil shale formation's exposure to
.heat necessary to form
both gaseous and liquefied hydrocarbons. It may Jake .between 2-4 years for
the formation of
sufficient kerogen to be commercially recoverable. After. that recovery may
occur on. a
commercial level for between 3 ¨ 30 years rmore. .
=
= =
A product' recovery system 360 is constructed at site 22.. .Product=recoVery.
system 360 =
=
.may be coupled with injection wells 338 for collection of gaseous and
liquefied hydrocarbons '
that are released during the retort process- or May be perforation recovery
wells. An illuStration
of the energy flow of System 20 with retort system 320 -(Figure 8) for, oil
shale retorting =
operations, as shown in Figure 9, include S nuclear energy 346 generated from
nuclear reactor 26.
=
15. Salt is delivered from salt injection system 334 to molten Salt
generator 328. = =
=.
= Nuclear energy 346 creates thermal energy 332 that is. transferred
to molten salt generator
= 328 for producing molten salt 336. Molten salt 336 is delivered to pumps
330 .and -pump energy
348 delivers molten salt 3.36 to retort injection wells 338 with sufficient
energy 350 to transfer,
.molten salt 336 to the fractured .oil shale formations for heat inducement.
The exposure of the oil
= 20. shale to heat accelerates the maturation of the .hydrocarbon
precursors, such as kerogen, which .
forms. liquefied and gaseous hydrocarbons. 'During the retort operations,
hydrocarbon products =
362 accumulate. Hydrocarbon products 362 are extracted and collected by
product recovery =
system 360. Residual molten salt 364 from the retorting operations are
recovered via a salt
-recovery system 345 and reinjected to Molten salt generator 328, via pumps-
33I and salt injection
25 system 334. It is envisioned that salt recovery system 345 is employed
to minimize the
consumption of salt Used to retort the fractured oil. shale formation. .
=
. .
In another alternate embodiment, as shown in Figure 10, system 20 includes a
retort
system 420 for retort operations relating to the fractured oil shale
formations at site 22, similar to
those described. Site 22 is prepared for installation .and related
construction of retort system 420, =
18
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which includes a steam generator, oscillators and thermal transfer system
components, as will be
=
described. =
=
.Retort system 420 employs heat generated by _oscillators', which are mounted
with the
fractured oil shale formations cf site 22. The heat generated induces heating
of the fractUred oil
. shale formations to accelerate the maturation process of hydrogen
precursor's, as discussed.
Nuclear reactor 26 discussed above, is a thermal source that cooperates with a
steam generator
228 to ppWer a stearn turbine 230 for generating the eleetric energy to retort
The fractured oil
shale. formation in-Situ. Nuclear reactor 26 is sized to .be located at or
near' site 22 .of the .
fractured oil shale formation. It is envisioned that the .electric capacity
rating of nuclear reactor
= . 10 26 is between 50 MWe to 3000 MWe. - It is= Contemplated that the
hydrogen generated by nuclear
= reactor 26 can be used-to- enhance the value of carbon bearing material,
which may resemble
char, so -it will be recoverable. A hydrogen generator (not shown),
eitherelectrolysis, thermal or
. = other may be attached to the nualear reactor 26 to generate hydrogen
for this use: -
Water supply 34 delivers water to steam generator 228, which is constructed
and installed .
at.site 22. Nticlear reactor 26 is Coupled to steam generator 228, in a manner
as is known to one
=
skilled in the art, for the transfer or thermal energy 232. System 20* employs
steam generator
228, in cooperation With nuclear reactor 26 as the thermal source,' to produce
steam 236 to .
. activate steam turbine 230 for retort of the fractured oil shale formations.
=
=
. Steam generator 228 is coupled to steam turbine 230, in a mariner as is.
known to one =
skilled in the art. Steam 236 from steam generator 228 flows into steam
turbine 230 to provide =
.mechanical energy 237 to an electric generator 234. Steam turbine 230 is
coupled to electric
=
generator 234, and mechanical energy 237 generates current 239 from electric
generator 234. It .
is contemplated that current 239 may include alternating current or direct
current.
. Current 239 fro=m electric. generator 234 is delivered to
oscillators 438. = The electric
povier delivered to oscillators 438 via current 239 creates a radio frequency
having a .wavelength
where the attenuation is compatible.with the well spacing to provide
substantially uniform heat.
.A prOduct'recovery system 460 is constructed at site 22: Product recovery
sy'stem' 460 is.
connected with the recovery wells for collection of gaseous and liquefied
hydrocarbons that are .
19
CA 02641521 2013-11-08
=
released during the retort process. An illustration of the energy flow of
system 20 with retort
system 420 (Figure 10) for oil shale retorting operations, as shown in Figure
11, includes nuclear
energy 446 generated from nuclear reactor 26. Nuclear energy 446 creates
thermal energy 232
that is transferred to steam generator 228 for producing steam. Steam 236 is
delivered to steam
turbine 230, which produces mechanical energy 237. Mechanical energy 237
generates current
239 from electric generator 234.
Current 239 delivers electric energy to oscillators 438 to create radio
frequencies 241 to
heat the fractured oil shale formations for heat inducement. The exposure of
the oil shale to heat
accelerates the maturation of the hydrocarbon precursors, such as kerogen,
which forms liquefied
and gaseous hydrocarbons. During the retort operations, hydrocarbon products
accumulate. The
hydrocarbon products are extracted and collected by product recovery system
460.
It will be understood that various modifications may be made to the
embodiments
disclosed herein. Therefore, the above description should not be construed as
limiting, but
merely as exemplification of the various embodiments. Those skilled in the art
will envision
other modifications within the scope of the claims appended hereto.
